Reproduction steps:
1. Create a new project
2. Install Entities package in Package Manager (Window > Package Management > Package Manager > Entities)
3. Right-click on Hierarchy window and create a Sub Scene (New Sub Scene > Empty Scene…)
4. Enter Play mode
5. Expand DontDestroyOnLoad GameObject in Hierarchy and drag New Game Object to the Project window to create a Prefab
6. Observe the Editor

Actual result: Editor crashes
Expected result: Editor doesn’t crash

Reproducible with: 1.4.4 (6000.3.7f1), 6.4.0 (6000.4.0b7), 6.5.0 (6000.5.0a6)
Couldn’t reproduce with: 1.4.4 (6000.0.66f2) (No New Game Object)

Reproduced on: macOS Sequoia 26.2 (M4)

Note: First few lines of Stack Trace:
{code:java}
#0  0x00000106a5d6bc in GameObject::QueryComponentByType(Unity::Type const) const
#1  0x00000105357598 in GetOriginalSourceOrVariantRoot(Object)
#2  0x00000104d0492c in DragAndDropPrefabsFromHierarchyToProjectWindow(std::__1::set<GameObject, std::__1::less<GameObject>, std::__1::allocator<GameObject>> const&, Object, Prefab*, UnityGUID const&, bool, int)
#3  0x00000104d0aeb8 in ProjectWindowDrag(UnityGUID const&, PPtr<Object>, bool)
#4  0x00000104d1a578 in InternalEditorUtilityBindings::ProjectWindowDrag(ScriptingObjectPtr, bool){code}